APA

Mining Engineering Series, . (1961). Rock mechanics. Symposium. 4. University park, PA, 1961. Proceedings. ( Pennsylvania State University. Mineral Industries Experiment Station. Bulletin nr 76). University Park, PA: Mining Engineering Series.

Chicago

Mining Engineering Series, . 1961. Rock mechanics. Symposium. 4. University park, PA, 1961. Proceedings. ( Pennsylvania State University. Mineral Industries Experiment Station. Bulletin nr 76). University Park, PA: Mining Engineering Series.

Harvard

Mining Engineering Series, . (1961). Rock mechanics. Symposium. 4. University park, PA, 1961. Proceedings. ( Pennsylvania State University. Mineral Industries Experiment Station. Bulletin nr 76). University Park, PA: Mining Engineering Series.

MLA

Mining Engineering Series, . Rock mechanics. Symposium. 4. University park, PA, 1961. Proceedings. ( Pennsylvania State University. Mineral Industries Experiment Station. Bulletin nr 76). University Park, PA: Mining Engineering Series. 1961.